Using the separation of endotoxin (pyrogens) from albumin as an example, it has been verified that continuous convective electrophoresis can be applied for the purification of a polyelectrolyte sample from complex-forming charged impurities. In a one-stage process, 40% of endotoxin-contaminated albumin could be depyrogenized (<1 mug/L). A multistage process would further increase the yield of depyrogenized albumin, but a complete recovery of depyrogenized albumin is not possible because endotoxins tend to form complexes with albumin. However, the presented method demonstrates a simple way to purify a considerable amount of contaminated albumin without introducing, e.g., detergents or complex inactivation reagents.